Home | History | Annotate | Download | only in vm
      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 /*
     18  * Dalvik initialization, shutdown, and command-line argument processing.
     19  */
     20 #define __STDC_LIMIT_MACROS
     21 #include <stdlib.h>
     22 #include <stdio.h>
     23 #include <signal.h>
     24 #include <limits.h>
     25 #include <ctype.h>
     26 #include <sys/wait.h>
     27 #include <unistd.h>
     28 
     29 #include "Dalvik.h"
     30 #include "test/Test.h"
     31 #include "mterp/Mterp.h"
     32 #include "Hash.h"
     33 
     34 #define kMinHeapStartSize   (1*1024*1024)
     35 #define kMinHeapSize        (2*1024*1024)
     36 #define kMaxHeapSize        (1*1024*1024*1024)
     37 
     38 /*
     39  * Register VM-agnostic native methods for system classes.
     40  */
     41 extern int jniRegisterSystemMethods(JNIEnv* env);
     42 
     43 /* fwd */
     44 static bool registerSystemNatives(JNIEnv* pEnv);
     45 static bool initJdwp();
     46 static bool initZygote();
     47 
     48 
     49 /* global state */
     50 struct DvmGlobals gDvm;
     51 struct DvmJniGlobals gDvmJni;
     52 
     53 /* JIT-specific global state */
     54 #if defined(WITH_JIT)
     55 struct DvmJitGlobals gDvmJit;
     56 
     57 #if defined(WITH_JIT_TUNING)
     58 /*
     59  * Track the number of hits in the inline cache for predicted chaining.
     60  * Use an ugly global variable here since it is accessed in assembly code.
     61  */
     62 int gDvmICHitCount;
     63 #endif
     64 
     65 #endif
     66 
     67 /*
     68  * Show usage.
     69  *
     70  * We follow the tradition of unhyphenated compound words.
     71  */
     72 static void usage(const char* progName)
     73 {
     74     dvmFprintf(stderr, "%s: [options] class [argument ...]\n", progName);
     75     dvmFprintf(stderr, "%s: [options] -jar file.jar [argument ...]\n",progName);
     76     dvmFprintf(stderr, "\n");
     77     dvmFprintf(stderr, "The following standard options are recognized:\n");
     78     dvmFprintf(stderr, "  -classpath classpath\n");
     79     dvmFprintf(stderr, "  -Dproperty=value\n");
     80     dvmFprintf(stderr, "  -verbose:tag  ('gc', 'jni', or 'class')\n");
     81     dvmFprintf(stderr, "  -ea[:<package name>... |:<class name>]\n");
     82     dvmFprintf(stderr, "  -da[:<package name>... |:<class name>]\n");
     83     dvmFprintf(stderr, "   (-enableassertions, -disableassertions)\n");
     84     dvmFprintf(stderr, "  -esa\n");
     85     dvmFprintf(stderr, "  -dsa\n");
     86     dvmFprintf(stderr,
     87                 "   (-enablesystemassertions, -disablesystemassertions)\n");
     88     dvmFprintf(stderr, "  -showversion\n");
     89     dvmFprintf(stderr, "  -help\n");
     90     dvmFprintf(stderr, "\n");
     91     dvmFprintf(stderr, "The following extended options are recognized:\n");
     92     dvmFprintf(stderr, "  -Xrunjdwp:<options>\n");
     93     dvmFprintf(stderr, "  -Xbootclasspath:bootclasspath\n");
     94     dvmFprintf(stderr, "  -Xcheck:tag  (e.g. 'jni')\n");
     95     dvmFprintf(stderr, "  -XmsN  (min heap, must be multiple of 1K, >= 1MB)\n");
     96     dvmFprintf(stderr, "  -XmxN  (max heap, must be multiple of 1K, >= 2MB)\n");
     97     dvmFprintf(stderr, "  -XssN  (stack size, >= %dKB, <= %dKB)\n",
     98         kMinStackSize / 1024, kMaxStackSize / 1024);
     99     dvmFprintf(stderr, "  -Xverify:{none,remote,all}\n");
    100     dvmFprintf(stderr, "  -Xrs\n");
    101 #if defined(WITH_JIT)
    102     dvmFprintf(stderr,
    103                 "  -Xint  (extended to accept ':portable', ':fast' and ':jit')\n");
    104 #else
    105     dvmFprintf(stderr,
    106                 "  -Xint  (extended to accept ':portable' and ':fast')\n");
    107 #endif
    108     dvmFprintf(stderr, "\n");
    109     dvmFprintf(stderr, "These are unique to Dalvik:\n");
    110     dvmFprintf(stderr, "  -Xzygote\n");
    111     dvmFprintf(stderr, "  -Xdexopt:{none,verified,all,full}\n");
    112     dvmFprintf(stderr, "  -Xnoquithandler\n");
    113     dvmFprintf(stderr,
    114                 "  -Xjnigreflimit:N  (must be multiple of 100, >= 200)\n");
    115     dvmFprintf(stderr, "  -Xjniopts:{warnonly,forcecopy}\n");
    116     dvmFprintf(stderr, "  -Xjnitrace:substring (eg NativeClass or nativeMethod)\n");
    117     dvmFprintf(stderr, "  -Xstacktracefile:<filename>\n");
    118     dvmFprintf(stderr, "  -Xgc:[no]precise\n");
    119     dvmFprintf(stderr, "  -Xgc:[no]preverify\n");
    120     dvmFprintf(stderr, "  -Xgc:[no]postverify\n");
    121     dvmFprintf(stderr, "  -Xgc:[no]concurrent\n");
    122     dvmFprintf(stderr, "  -Xgc:[no]verifycardtable\n");
    123     dvmFprintf(stderr, "  -XX:+DisableExplicitGC\n");
    124     dvmFprintf(stderr, "  -X[no]genregmap\n");
    125     dvmFprintf(stderr, "  -Xverifyopt:[no]checkmon\n");
    126     dvmFprintf(stderr, "  -Xcheckdexsum\n");
    127 #if defined(WITH_JIT)
    128     dvmFprintf(stderr, "  -Xincludeselectedop\n");
    129     dvmFprintf(stderr, "  -Xjitop:hexopvalue[-endvalue]"
    130                        "[,hexopvalue[-endvalue]]*\n");
    131     dvmFprintf(stderr, "  -Xincludeselectedmethod\n");
    132     dvmFprintf(stderr, "  -Xjitthreshold:decimalvalue\n");
    133     dvmFprintf(stderr, "  -Xjitblocking\n");
    134     dvmFprintf(stderr, "  -Xjitmethod:signature[,signature]* "
    135                        "(eg Ljava/lang/String\\;replace)\n");
    136     dvmFprintf(stderr, "  -Xjitcheckcg\n");
    137     dvmFprintf(stderr, "  -Xjitverbose\n");
    138     dvmFprintf(stderr, "  -Xjitprofile\n");
    139     dvmFprintf(stderr, "  -Xjitdisableopt\n");
    140     dvmFprintf(stderr, "  -Xjitsuspendpoll\n");
    141 #endif
    142     dvmFprintf(stderr, "\n");
    143     dvmFprintf(stderr, "Configured with:"
    144         " debugger"
    145         " profiler"
    146         " hprof"
    147 #ifdef WITH_TRACKREF_CHECKS
    148         " trackref_checks"
    149 #endif
    150 #ifdef WITH_INSTR_CHECKS
    151         " instr_checks"
    152 #endif
    153 #ifdef WITH_EXTRA_OBJECT_VALIDATION
    154         " extra_object_validation"
    155 #endif
    156 #ifdef WITH_EXTRA_GC_CHECKS
    157         " extra_gc_checks"
    158 #endif
    159 #if !defined(NDEBUG) && defined(WITH_DALVIK_ASSERT)
    160         " dalvik_assert"
    161 #endif
    162 #ifdef WITH_JNI_STACK_CHECK
    163         " jni_stack_check"
    164 #endif
    165 #ifdef EASY_GDB
    166         " easy_gdb"
    167 #endif
    168 #ifdef CHECK_MUTEX
    169         " check_mutex"
    170 #endif
    171 #if defined(WITH_JIT)
    172         " jit(" ARCH_VARIANT ")"
    173 #endif
    174 #if defined(WITH_SELF_VERIFICATION)
    175         " self_verification"
    176 #endif
    177 #if ANDROID_SMP != 0
    178         " smp"
    179 #endif
    180     );
    181 #ifdef DVM_SHOW_EXCEPTION
    182     dvmFprintf(stderr, " show_exception=%d", DVM_SHOW_EXCEPTION);
    183 #endif
    184     dvmFprintf(stderr, "\n\n");
    185 }
    186 
    187 /*
    188  * Show helpful information on JDWP options.
    189  */
    190 static void showJdwpHelp()
    191 {
    192     dvmFprintf(stderr,
    193         "Example: -Xrunjdwp:transport=dt_socket,address=8000,server=y\n");
    194     dvmFprintf(stderr,
    195         "Example: -Xrunjdwp:transport=dt_socket,address=localhost:6500,server=n\n");
    196 }
    197 
    198 /*
    199  * Show version and copyright info.
    200  */
    201 static void showVersion()
    202 {
    203     dvmFprintf(stdout, "DalvikVM version %d.%d.%d\n",
    204         DALVIK_MAJOR_VERSION, DALVIK_MINOR_VERSION, DALVIK_BUG_VERSION);
    205     dvmFprintf(stdout,
    206         "Copyright (C) 2007 The Android Open Source Project\n\n"
    207         "This software is built from source code licensed under the "
    208         "Apache License,\n"
    209         "Version 2.0 (the \"License\"). You may obtain a copy of the "
    210         "License at\n\n"
    211         "     http://www.apache.org/licenses/LICENSE-2.0\n\n"
    212         "See the associated NOTICE file for this software for further "
    213         "details.\n");
    214 }
    215 
    216 /*
    217  * Parse a string of the form /[0-9]+[kKmMgG]?/, which is used to specify
    218  * memory sizes.  [kK] indicates kilobytes, [mM] megabytes, and
    219  * [gG] gigabytes.
    220  *
    221  * "s" should point just past the "-Xm?" part of the string.
    222  * "min" specifies the lowest acceptable value described by "s".
    223  * "div" specifies a divisor, e.g. 1024 if the value must be a multiple
    224  * of 1024.
    225  *
    226  * The spec says the -Xmx and -Xms options must be multiples of 1024.  It
    227  * doesn't say anything about -Xss.
    228  *
    229  * Returns 0 (a useless size) if "s" is malformed or specifies a low or
    230  * non-evenly-divisible value.
    231  */
    232 static size_t parseMemOption(const char *s, size_t div)
    233 {
    234     /* strtoul accepts a leading [+-], which we don't want,
    235      * so make sure our string starts with a decimal digit.
    236      */
    237     if (isdigit(*s)) {
    238         const char *s2;
    239         size_t val;
    240 
    241         val = strtoul(s, (char **)&s2, 10);
    242         if (s2 != s) {
    243             /* s2 should be pointing just after the number.
    244              * If this is the end of the string, the user
    245              * has specified a number of bytes.  Otherwise,
    246              * there should be exactly one more character
    247              * that specifies a multiplier.
    248              */
    249             if (*s2 != '\0') {
    250                 char c;
    251 
    252                 /* The remainder of the string is either a single multiplier
    253                  * character, or nothing to indicate that the value is in
    254                  * bytes.
    255                  */
    256                 c = *s2++;
    257                 if (*s2 == '\0') {
    258                     size_t mul;
    259 
    260                     if (c == '\0') {
    261                         mul = 1;
    262                     } else if (c == 'k' || c == 'K') {
    263                         mul = 1024;
    264                     } else if (c == 'm' || c == 'M') {
    265                         mul = 1024 * 1024;
    266                     } else if (c == 'g' || c == 'G') {
    267                         mul = 1024 * 1024 * 1024;
    268                     } else {
    269                         /* Unknown multiplier character.
    270                          */
    271                         return 0;
    272                     }
    273 
    274                     if (val <= SIZE_MAX / mul) {
    275                         val *= mul;
    276                     } else {
    277                         /* Clamp to a multiple of 1024.
    278                          */
    279                         val = SIZE_MAX & ~(1024-1);
    280                     }
    281                 } else {
    282                     /* There's more than one character after the
    283                      * numeric part.
    284                      */
    285                     return 0;
    286                 }
    287             }
    288 
    289             /* The man page says that a -Xm value must be
    290              * a multiple of 1024.
    291              */
    292             if (val % div == 0) {
    293                 return val;
    294             }
    295         }
    296     }
    297 
    298     return 0;
    299 }
    300 
    301 /*
    302  * Handle one of the JDWP name/value pairs.
    303  *
    304  * JDWP options are:
    305  *  help: if specified, show help message and bail
    306  *  transport: may be dt_socket or dt_shmem
    307  *  address: for dt_socket, "host:port", or just "port" when listening
    308  *  server: if "y", wait for debugger to attach; if "n", attach to debugger
    309  *  timeout: how long to wait for debugger to connect / listen
    310  *
    311  * Useful with server=n (these aren't supported yet):
    312  *  onthrow=<exception-name>: connect to debugger when exception thrown
    313  *  onuncaught=y|n: connect to debugger when uncaught exception thrown
    314  *  launch=<command-line>: launch the debugger itself
    315  *
    316  * The "transport" option is required, as is "address" if server=n.
    317  */
    318 static bool handleJdwpOption(const char* name, const char* value)
    319 {
    320     if (strcmp(name, "transport") == 0) {
    321         if (strcmp(value, "dt_socket") == 0) {
    322             gDvm.jdwpTransport = kJdwpTransportSocket;
    323         } else if (strcmp(value, "dt_android_adb") == 0) {
    324             gDvm.jdwpTransport = kJdwpTransportAndroidAdb;
    325         } else {
    326             LOGE("JDWP transport '%s' not supported", value);
    327             return false;
    328         }
    329     } else if (strcmp(name, "server") == 0) {
    330         if (*value == 'n')
    331             gDvm.jdwpServer = false;
    332         else if (*value == 'y')
    333             gDvm.jdwpServer = true;
    334         else {
    335             LOGE("JDWP option 'server' must be 'y' or 'n'");
    336             return false;
    337         }
    338     } else if (strcmp(name, "suspend") == 0) {
    339         if (*value == 'n')
    340             gDvm.jdwpSuspend = false;
    341         else if (*value == 'y')
    342             gDvm.jdwpSuspend = true;
    343         else {
    344             LOGE("JDWP option 'suspend' must be 'y' or 'n'");
    345             return false;
    346         }
    347     } else if (strcmp(name, "address") == 0) {
    348         /* this is either <port> or <host>:<port> */
    349         const char* colon = strchr(value, ':');
    350         char* end;
    351         long port;
    352 
    353         if (colon != NULL) {
    354             free(gDvm.jdwpHost);
    355             gDvm.jdwpHost = (char*) malloc(colon - value +1);
    356             strncpy(gDvm.jdwpHost, value, colon - value +1);
    357             gDvm.jdwpHost[colon-value] = '\0';
    358             value = colon + 1;
    359         }
    360         if (*value == '\0') {
    361             LOGE("JDWP address missing port");
    362             return false;
    363         }
    364         port = strtol(value, &end, 10);
    365         if (*end != '\0') {
    366             LOGE("JDWP address has junk in port field '%s'", value);
    367             return false;
    368         }
    369         gDvm.jdwpPort = port;
    370     } else if (strcmp(name, "launch") == 0 ||
    371                strcmp(name, "onthrow") == 0 ||
    372                strcmp(name, "oncaught") == 0 ||
    373                strcmp(name, "timeout") == 0)
    374     {
    375         /* valid but unsupported */
    376         LOGI("Ignoring JDWP option '%s'='%s'", name, value);
    377     } else {
    378         LOGI("Ignoring unrecognized JDWP option '%s'='%s'", name, value);
    379     }
    380 
    381     return true;
    382 }
    383 
    384 /*
    385  * Parse the latter half of a -Xrunjdwp/-agentlib:jdwp= string, e.g.:
    386  * "transport=dt_socket,address=8000,server=y,suspend=n"
    387  */
    388 static bool parseJdwpOptions(const char* str)
    389 {
    390     char* mangle = strdup(str);
    391     char* name = mangle;
    392     bool result = false;
    393 
    394     /*
    395      * Process all of the name=value pairs.
    396      */
    397     while (true) {
    398         char* value;
    399         char* comma;
    400 
    401         value = strchr(name, '=');
    402         if (value == NULL) {
    403             LOGE("JDWP opts: garbage at '%s'", name);
    404             goto bail;
    405         }
    406 
    407         comma = strchr(name, ',');      // use name, not value, for safety
    408         if (comma != NULL) {
    409             if (comma < value) {
    410                 LOGE("JDWP opts: found comma before '=' in '%s'", mangle);
    411                 goto bail;
    412             }
    413             *comma = '\0';
    414         }
    415 
    416         *value++ = '\0';        // stomp the '='
    417 
    418         if (!handleJdwpOption(name, value))
    419             goto bail;
    420 
    421         if (comma == NULL) {
    422             /* out of options */
    423             break;
    424         }
    425         name = comma+1;
    426     }
    427 
    428     /*
    429      * Make sure the combination of arguments makes sense.
    430      */
    431     if (gDvm.jdwpTransport == kJdwpTransportUnknown) {
    432         LOGE("JDWP opts: must specify transport");
    433         goto bail;
    434     }
    435     if (!gDvm.jdwpServer && (gDvm.jdwpHost == NULL || gDvm.jdwpPort == 0)) {
    436         LOGE("JDWP opts: when server=n, must specify host and port");
    437         goto bail;
    438     }
    439     // transport mandatory
    440     // outbound server address
    441 
    442     gDvm.jdwpConfigured = true;
    443     result = true;
    444 
    445 bail:
    446     free(mangle);
    447     return result;
    448 }
    449 
    450 /*
    451  * Handle one of the four kinds of assertion arguments.
    452  *
    453  * "pkgOrClass" is the last part of an enable/disable line.  For a package
    454  * the arg looks like "-ea:com.google.fubar...", for a class it looks
    455  * like "-ea:com.google.fubar.Wahoo".  The string we get starts at the ':'.
    456  *
    457  * For system assertions (-esa/-dsa), "pkgOrClass" is NULL.
    458  *
    459  * Multiple instances of these arguments can be specified, e.g. you can
    460  * enable assertions for a package and then disable them for one class in
    461  * the package.
    462  */
    463 static bool enableAssertions(const char* pkgOrClass, bool enable)
    464 {
    465     AssertionControl* pCtrl = &gDvm.assertionCtrl[gDvm.assertionCtrlCount++];
    466     pCtrl->enable = enable;
    467 
    468     if (pkgOrClass == NULL) {
    469         /* enable or disable for all system classes */
    470         pCtrl->isPackage = false;
    471         pCtrl->pkgOrClass = NULL;
    472         pCtrl->pkgOrClassLen = 0;
    473     } else {
    474         if (*pkgOrClass == '\0') {
    475             /* global enable/disable for all but system */
    476             pCtrl->isPackage = false;
    477             pCtrl->pkgOrClass = strdup("");
    478             pCtrl->pkgOrClassLen = 0;
    479         } else {
    480             pCtrl->pkgOrClass = dvmDotToSlash(pkgOrClass+1);    // skip ':'
    481             if (pCtrl->pkgOrClass == NULL) {
    482                 /* can happen if class name includes an illegal '/' */
    483                 LOGW("Unable to process assertion arg '%s'", pkgOrClass);
    484                 return false;
    485             }
    486 
    487             int len = strlen(pCtrl->pkgOrClass);
    488             if (len >= 3 && strcmp(pCtrl->pkgOrClass + len-3, "///") == 0) {
    489                 /* mark as package, truncate two of the three slashes */
    490                 pCtrl->isPackage = true;
    491                 *(pCtrl->pkgOrClass + len-2) = '\0';
    492                 pCtrl->pkgOrClassLen = len - 2;
    493             } else {
    494                 /* just a class */
    495                 pCtrl->isPackage = false;
    496                 pCtrl->pkgOrClassLen = len;
    497             }
    498         }
    499     }
    500 
    501     return true;
    502 }
    503 
    504 /*
    505  * Turn assertions on when requested to do so by the Zygote.
    506  *
    507  * This is a bit sketchy.  We can't (easily) go back and fiddle with all
    508  * of the classes that have already been initialized, so this only
    509  * affects classes that have yet to be loaded.  If some or all assertions
    510  * have been enabled through some other means, we don't want to mess with
    511  * it here, so we do nothing.  Finally, we assume that there's room in
    512  * "assertionCtrl" to hold at least one entry; this is guaranteed by the
    513  * allocator.
    514  *
    515  * This must only be called from the main thread during zygote init.
    516  */
    517 void dvmLateEnableAssertions()
    518 {
    519     if (gDvm.assertionCtrl == NULL) {
    520         LOGD("Not late-enabling assertions: no assertionCtrl array");
    521         return;
    522     } else if (gDvm.assertionCtrlCount != 0) {
    523         LOGD("Not late-enabling assertions: some asserts already configured");
    524         return;
    525     }
    526     LOGD("Late-enabling assertions");
    527 
    528     /* global enable for all but system */
    529     AssertionControl* pCtrl = gDvm.assertionCtrl;
    530     pCtrl->pkgOrClass = strdup("");
    531     pCtrl->pkgOrClassLen = 0;
    532     pCtrl->isPackage = false;
    533     pCtrl->enable = true;
    534     gDvm.assertionCtrlCount = 1;
    535 }
    536 
    537 
    538 /*
    539  * Release memory associated with the AssertionCtrl array.
    540  */
    541 static void freeAssertionCtrl()
    542 {
    543     int i;
    544 
    545     for (i = 0; i < gDvm.assertionCtrlCount; i++)
    546         free(gDvm.assertionCtrl[i].pkgOrClass);
    547     free(gDvm.assertionCtrl);
    548 }
    549 
    550 #if defined(WITH_JIT)
    551 /* Parse -Xjitop to selectively turn on/off certain opcodes for JIT */
    552 static void processXjitop(const char *opt)
    553 {
    554     if (opt[7] == ':') {
    555         const char *startPtr = &opt[8];
    556         char *endPtr = NULL;
    557 
    558         do {
    559             long startValue, endValue;
    560 
    561             startValue = strtol(startPtr, &endPtr, 16);
    562             if (startPtr != endPtr) {
    563                 /* Just in case value is out of range */
    564                 startValue %= kNumPackedOpcodes;
    565 
    566                 if (*endPtr == '-') {
    567                     endValue = strtol(endPtr+1, &endPtr, 16);
    568                     endValue %= kNumPackedOpcodes;
    569                 } else {
    570                     endValue = startValue;
    571                 }
    572 
    573                 for (; startValue <= endValue; startValue++) {
    574                     LOGW("Dalvik opcode %x is selected for debugging",
    575                          (unsigned int) startValue);
    576                     /* Mark the corresponding bit to 1 */
    577                     gDvmJit.opList[startValue >> 3] |= 1 << (startValue & 0x7);
    578                 }
    579 
    580                 if (*endPtr == 0) {
    581                     break;
    582                 }
    583 
    584                 startPtr = endPtr + 1;
    585 
    586                 continue;
    587             } else {
    588                 if (*endPtr != 0) {
    589                     dvmFprintf(stderr,
    590                         "Warning: Unrecognized opcode value substring "
    591                         "%s\n", endPtr);
    592                 }
    593                 break;
    594             }
    595         } while (1);
    596     } else {
    597         int i;
    598         for (i = 0; i < (kNumPackedOpcodes+7)/8; i++) {
    599             gDvmJit.opList[i] = 0xff;
    600         }
    601         dvmFprintf(stderr, "Warning: select all opcodes\n");
    602     }
    603 }
    604 
    605 /* Parse -Xjitmethod to selectively turn on/off certain methods for JIT */
    606 static void processXjitmethod(const char *opt)
    607 {
    608     char *buf = strdup(&opt[12]);
    609     char *start, *end;
    610 
    611     gDvmJit.methodTable = dvmHashTableCreate(8, NULL);
    612 
    613     start = buf;
    614     /*
    615      * Break comma-separated method signatures and enter them into the hash
    616      * table individually.
    617      */
    618     do {
    619         int hashValue;
    620 
    621         end = strchr(start, ',');
    622         if (end) {
    623             *end = 0;
    624         }
    625 
    626         hashValue = dvmComputeUtf8Hash(start);
    627 
    628         dvmHashTableLookup(gDvmJit.methodTable, hashValue,
    629                            strdup(start),
    630                            (HashCompareFunc) strcmp, true);
    631         if (end) {
    632             start = end + 1;
    633         } else {
    634             break;
    635         }
    636     } while (1);
    637     free(buf);
    638 }
    639 #endif
    640 
    641 /*
    642  * Process an argument vector full of options.  Unlike standard C programs,
    643  * argv[0] does not contain the name of the program.
    644  *
    645  * If "ignoreUnrecognized" is set, we ignore options starting with "-X" or "_"
    646  * that we don't recognize.  Otherwise, we return with an error as soon as
    647  * we see anything we can't identify.
    648  *
    649  * Returns 0 on success, -1 on failure, and 1 for the special case of
    650  * "-version" where we want to stop without showing an error message.
    651  */
    652 static int processOptions(int argc, const char* const argv[],
    653     bool ignoreUnrecognized)
    654 {
    655     int i;
    656 
    657     LOGV("VM options (%d):", argc);
    658     for (i = 0; i < argc; i++)
    659         LOGV("  %d: '%s'", i, argv[i]);
    660 
    661     /*
    662      * Over-allocate AssertionControl array for convenience.  If allocated,
    663      * the array must be able to hold at least one entry, so that the
    664      * zygote-time activation can do its business.
    665      */
    666     assert(gDvm.assertionCtrl == NULL);
    667     if (argc > 0) {
    668         gDvm.assertionCtrl =
    669             (AssertionControl*) malloc(sizeof(AssertionControl) * argc);
    670         if (gDvm.assertionCtrl == NULL)
    671             return -1;
    672         assert(gDvm.assertionCtrlCount == 0);
    673     }
    674 
    675     for (i = 0; i < argc; i++) {
    676         if (strcmp(argv[i], "-help") == 0) {
    677             /* show usage and stop */
    678             return -1;
    679 
    680         } else if (strcmp(argv[i], "-version") == 0) {
    681             /* show version and stop */
    682             showVersion();
    683             return 1;
    684         } else if (strcmp(argv[i], "-showversion") == 0) {
    685             /* show version and continue */
    686             showVersion();
    687 
    688         } else if (strcmp(argv[i], "-classpath") == 0 ||
    689                    strcmp(argv[i], "-cp") == 0)
    690         {
    691             /* set classpath */
    692             if (i == argc-1) {
    693                 dvmFprintf(stderr, "Missing classpath path list\n");
    694                 return -1;
    695             }
    696             free(gDvm.classPathStr); /* in case we have compiled-in default */
    697             gDvm.classPathStr = strdup(argv[++i]);
    698 
    699         } else if (strncmp(argv[i], "-Xbootclasspath:",
    700                 sizeof("-Xbootclasspath:")-1) == 0)
    701         {
    702             /* set bootclasspath */
    703             const char* path = argv[i] + sizeof("-Xbootclasspath:")-1;
    704 
    705             if (*path == '\0') {
    706                 dvmFprintf(stderr, "Missing bootclasspath path list\n");
    707                 return -1;
    708             }
    709             free(gDvm.bootClassPathStr);
    710             gDvm.bootClassPathStr = strdup(path);
    711 
    712         } else if (strncmp(argv[i], "-Xbootclasspath/a:",
    713                 sizeof("-Xbootclasspath/a:")-1) == 0) {
    714             const char* appPath = argv[i] + sizeof("-Xbootclasspath/a:")-1;
    715 
    716             if (*(appPath) == '\0') {
    717                 dvmFprintf(stderr, "Missing appending bootclasspath path list\n");
    718                 return -1;
    719             }
    720             char* allPath;
    721 
    722             if (asprintf(&allPath, "%s:%s", gDvm.bootClassPathStr, appPath) < 0) {
    723                 dvmFprintf(stderr, "Can't append to bootclasspath path list\n");
    724                 return -1;
    725             }
    726             free(gDvm.bootClassPathStr);
    727             gDvm.bootClassPathStr = allPath;
    728 
    729         } else if (strncmp(argv[i], "-Xbootclasspath/p:",
    730                 sizeof("-Xbootclasspath/p:")-1) == 0) {
    731             const char* prePath = argv[i] + sizeof("-Xbootclasspath/p:")-1;
    732 
    733             if (*(prePath) == '\0') {
    734                 dvmFprintf(stderr, "Missing prepending bootclasspath path list\n");
    735                 return -1;
    736             }
    737             char* allPath;
    738 
    739             if (asprintf(&allPath, "%s:%s", prePath, gDvm.bootClassPathStr) < 0) {
    740                 dvmFprintf(stderr, "Can't prepend to bootclasspath path list\n");
    741                 return -1;
    742             }
    743             free(gDvm.bootClassPathStr);
    744             gDvm.bootClassPathStr = allPath;
    745 
    746         } else if (strncmp(argv[i], "-D", 2) == 0) {
    747             /* Properties are handled in managed code. We just check syntax. */
    748             if (strchr(argv[i], '=') == NULL) {
    749                 dvmFprintf(stderr, "Bad system property setting: \"%s\"\n",
    750                     argv[i]);
    751                 return -1;
    752             }
    753             gDvm.properties->push_back(argv[i] + 2);
    754 
    755         } else if (strcmp(argv[i], "-jar") == 0) {
    756             // TODO: handle this; name of jar should be in argv[i+1]
    757             dvmFprintf(stderr, "-jar not yet handled\n");
    758             assert(false);
    759 
    760         } else if (strncmp(argv[i], "-Xms", 4) == 0) {
    761             size_t val = parseMemOption(argv[i]+4, 1024);
    762             if (val != 0) {
    763                 if (val >= kMinHeapStartSize && val <= kMaxHeapSize) {
    764                     gDvm.heapStartingSize = val;
    765                 } else {
    766                     dvmFprintf(stderr,
    767                         "Invalid -Xms '%s', range is %dKB to %dKB\n",
    768                         argv[i], kMinHeapStartSize/1024, kMaxHeapSize/1024);
    769                     return -1;
    770                 }
    771             } else {
    772                 dvmFprintf(stderr, "Invalid -Xms option '%s'\n", argv[i]);
    773                 return -1;
    774             }
    775         } else if (strncmp(argv[i], "-Xmx", 4) == 0) {
    776             size_t val = parseMemOption(argv[i]+4, 1024);
    777             if (val != 0) {
    778                 if (val >= kMinHeapSize && val <= kMaxHeapSize) {
    779                     gDvm.heapMaximumSize = val;
    780                 } else {
    781                     dvmFprintf(stderr,
    782                         "Invalid -Xmx '%s', range is %dKB to %dKB\n",
    783                         argv[i], kMinHeapSize/1024, kMaxHeapSize/1024);
    784                     return -1;
    785                 }
    786             } else {
    787                 dvmFprintf(stderr, "Invalid -Xmx option '%s'\n", argv[i]);
    788                 return -1;
    789             }
    790         } else if (strncmp(argv[i], "-XX:HeapGrowthLimit=", 20) == 0) {
    791             size_t val = parseMemOption(argv[i] + 20, 1024);
    792             if (val != 0) {
    793                 gDvm.heapGrowthLimit = val;
    794             } else {
    795                 dvmFprintf(stderr, "Invalid -XX:HeapGrowthLimit option '%s'\n", argv[i]);
    796                 return -1;
    797             }
    798         } else if (strncmp(argv[i], "-Xss", 4) == 0) {
    799             size_t val = parseMemOption(argv[i]+4, 1);
    800             if (val != 0) {
    801                 if (val >= kMinStackSize && val <= kMaxStackSize) {
    802                     gDvm.stackSize = val;
    803                 } else {
    804                     dvmFprintf(stderr, "Invalid -Xss '%s', range is %d to %d\n",
    805                         argv[i], kMinStackSize, kMaxStackSize);
    806                     return -1;
    807                 }
    808             } else {
    809                 dvmFprintf(stderr, "Invalid -Xss option '%s'\n", argv[i]);
    810                 return -1;
    811             }
    812 
    813         } else if (strncmp(argv[i], "-XX:+DisableExplicitGC", 22) == 0) {
    814             gDvm.disableExplicitGc = true;
    815         } else if (strcmp(argv[i], "-verbose") == 0 ||
    816             strcmp(argv[i], "-verbose:class") == 0)
    817         {
    818             // JNI spec says "-verbose:gc,class" is valid, but cmd line
    819             // doesn't work that way; may want to support.
    820             gDvm.verboseClass = true;
    821         } else if (strcmp(argv[i], "-verbose:jni") == 0) {
    822             gDvm.verboseJni = true;
    823         } else if (strcmp(argv[i], "-verbose:gc") == 0) {
    824             gDvm.verboseGc = true;
    825         } else if (strcmp(argv[i], "-verbose:shutdown") == 0) {
    826             gDvm.verboseShutdown = true;
    827 
    828         } else if (strncmp(argv[i], "-enableassertions", 17) == 0) {
    829             enableAssertions(argv[i] + 17, true);
    830         } else if (strncmp(argv[i], "-ea", 3) == 0) {
    831             enableAssertions(argv[i] + 3, true);
    832         } else if (strncmp(argv[i], "-disableassertions", 18) == 0) {
    833             enableAssertions(argv[i] + 18, false);
    834         } else if (strncmp(argv[i], "-da", 3) == 0) {
    835             enableAssertions(argv[i] + 3, false);
    836         } else if (strcmp(argv[i], "-enablesystemassertions") == 0 ||
    837                    strcmp(argv[i], "-esa") == 0)
    838         {
    839             enableAssertions(NULL, true);
    840         } else if (strcmp(argv[i], "-disablesystemassertions") == 0 ||
    841                    strcmp(argv[i], "-dsa") == 0)
    842         {
    843             enableAssertions(NULL, false);
    844 
    845         } else if (strncmp(argv[i], "-Xcheck:jni", 11) == 0) {
    846             /* nothing to do now -- was handled during JNI init */
    847 
    848         } else if (strcmp(argv[i], "-Xdebug") == 0) {
    849             /* accept but ignore */
    850 
    851         } else if (strncmp(argv[i], "-Xrunjdwp:", 10) == 0 ||
    852             strncmp(argv[i], "-agentlib:jdwp=", 15) == 0)
    853         {
    854             const char* tail;
    855 
    856             if (argv[i][1] == 'X')
    857                 tail = argv[i] + 10;
    858             else
    859                 tail = argv[i] + 15;
    860 
    861             if (strncmp(tail, "help", 4) == 0 || !parseJdwpOptions(tail)) {
    862                 showJdwpHelp();
    863                 return 1;
    864             }
    865         } else if (strcmp(argv[i], "-Xrs") == 0) {
    866             gDvm.reduceSignals = true;
    867         } else if (strcmp(argv[i], "-Xnoquithandler") == 0) {
    868             /* disables SIGQUIT handler thread while still blocking SIGQUIT */
    869             /* (useful if we don't want thread but system still signals us) */
    870             gDvm.noQuitHandler = true;
    871         } else if (strcmp(argv[i], "-Xzygote") == 0) {
    872             gDvm.zygote = true;
    873 #if defined(WITH_JIT)
    874             gDvmJit.runningInAndroidFramework = true;
    875 #endif
    876         } else if (strncmp(argv[i], "-Xdexopt:", 9) == 0) {
    877             if (strcmp(argv[i] + 9, "none") == 0)
    878                 gDvm.dexOptMode = OPTIMIZE_MODE_NONE;
    879             else if (strcmp(argv[i] + 9, "verified") == 0)
    880                 gDvm.dexOptMode = OPTIMIZE_MODE_VERIFIED;
    881             else if (strcmp(argv[i] + 9, "all") == 0)
    882                 gDvm.dexOptMode = OPTIMIZE_MODE_ALL;
    883             else if (strcmp(argv[i] + 9, "full") == 0)
    884                 gDvm.dexOptMode = OPTIMIZE_MODE_FULL;
    885             else {
    886                 dvmFprintf(stderr, "Unrecognized dexopt option '%s'\n",argv[i]);
    887                 return -1;
    888             }
    889         } else if (strncmp(argv[i], "-Xverify:", 9) == 0) {
    890             if (strcmp(argv[i] + 9, "none") == 0)
    891                 gDvm.classVerifyMode = VERIFY_MODE_NONE;
    892             else if (strcmp(argv[i] + 9, "remote") == 0)
    893                 gDvm.classVerifyMode = VERIFY_MODE_REMOTE;
    894             else if (strcmp(argv[i] + 9, "all") == 0)
    895                 gDvm.classVerifyMode = VERIFY_MODE_ALL;
    896             else {
    897                 dvmFprintf(stderr, "Unrecognized verify option '%s'\n",argv[i]);
    898                 return -1;
    899             }
    900         } else if (strncmp(argv[i], "-Xjnigreflimit:", 15) == 0) {
    901             int lim = atoi(argv[i] + 15);
    902             if (lim < 200 || (lim % 100) != 0) {
    903                 dvmFprintf(stderr, "Bad value for -Xjnigreflimit: '%s'\n",
    904                     argv[i]+15);
    905                 return -1;
    906             }
    907             gDvm.jniGrefLimit = lim;
    908         } else if (strncmp(argv[i], "-Xjnitrace:", 11) == 0) {
    909             gDvm.jniTrace = strdup(argv[i] + 11);
    910         } else if (strcmp(argv[i], "-Xlog-stdio") == 0) {
    911             gDvm.logStdio = true;
    912 
    913         } else if (strncmp(argv[i], "-Xint", 5) == 0) {
    914             if (argv[i][5] == ':') {
    915                 if (strcmp(argv[i] + 6, "portable") == 0)
    916                     gDvm.executionMode = kExecutionModeInterpPortable;
    917                 else if (strcmp(argv[i] + 6, "fast") == 0)
    918                     gDvm.executionMode = kExecutionModeInterpFast;
    919 #ifdef WITH_JIT
    920                 else if (strcmp(argv[i] + 6, "jit") == 0)
    921                     gDvm.executionMode = kExecutionModeJit;
    922 #endif
    923                 else {
    924                     dvmFprintf(stderr,
    925                         "Warning: Unrecognized interpreter mode %s\n",argv[i]);
    926                     /* keep going */
    927                 }
    928             } else {
    929                 /* disable JIT if it was enabled by default */
    930                 gDvm.executionMode = kExecutionModeInterpFast;
    931             }
    932 
    933         } else if (strncmp(argv[i], "-Xlockprofthreshold:", 20) == 0) {
    934             gDvm.lockProfThreshold = atoi(argv[i] + 20);
    935 
    936 #ifdef WITH_JIT
    937         } else if (strncmp(argv[i], "-Xjitop", 7) == 0) {
    938             processXjitop(argv[i]);
    939         } else if (strncmp(argv[i], "-Xjitmethod", 11) == 0) {
    940             processXjitmethod(argv[i]);
    941         } else if (strncmp(argv[i], "-Xjitblocking", 13) == 0) {
    942           gDvmJit.blockingMode = true;
    943         } else if (strncmp(argv[i], "-Xjitthreshold:", 15) == 0) {
    944           gDvmJit.threshold = atoi(argv[i] + 15);
    945         } else if (strncmp(argv[i], "-Xincludeselectedop", 19) == 0) {
    946           gDvmJit.includeSelectedOp = true;
    947         } else if (strncmp(argv[i], "-Xincludeselectedmethod", 23) == 0) {
    948           gDvmJit.includeSelectedMethod = true;
    949         } else if (strncmp(argv[i], "-Xjitcheckcg", 12) == 0) {
    950           gDvmJit.checkCallGraph = true;
    951           /* Need to enable blocking mode due to stack crawling */
    952           gDvmJit.blockingMode = true;
    953         } else if (strncmp(argv[i], "-Xjitverbose", 12) == 0) {
    954           gDvmJit.printMe = true;
    955         } else if (strncmp(argv[i], "-Xjitprofile", 12) == 0) {
    956           gDvmJit.profileMode = kTraceProfilingContinuous;
    957         } else if (strncmp(argv[i], "-Xjitdisableopt", 15) == 0) {
    958           /* Disable selected optimizations */
    959           if (argv[i][15] == ':') {
    960               sscanf(argv[i] + 16, "%x", &gDvmJit.disableOpt);
    961           /* Disable all optimizations */
    962           } else {
    963               gDvmJit.disableOpt = -1;
    964           }
    965         } else if (strncmp(argv[i], "-Xjitsuspendpoll", 16) == 0) {
    966           gDvmJit.genSuspendPoll = true;
    967 #endif
    968 
    969         } else if (strncmp(argv[i], "-Xstacktracefile:", 17) == 0) {
    970             gDvm.stackTraceFile = strdup(argv[i]+17);
    971 
    972         } else if (strcmp(argv[i], "-Xgenregmap") == 0) {
    973             gDvm.generateRegisterMaps = true;
    974         } else if (strcmp(argv[i], "-Xnogenregmap") == 0) {
    975             gDvm.generateRegisterMaps = false;
    976 
    977         } else if (strcmp(argv[i], "Xverifyopt:checkmon") == 0) {
    978             gDvm.monitorVerification = true;
    979         } else if (strcmp(argv[i], "Xverifyopt:nocheckmon") == 0) {
    980             gDvm.monitorVerification = false;
    981 
    982         } else if (strncmp(argv[i], "-Xgc:", 5) == 0) {
    983             if (strcmp(argv[i] + 5, "precise") == 0)
    984                 gDvm.preciseGc = true;
    985             else if (strcmp(argv[i] + 5, "noprecise") == 0)
    986                 gDvm.preciseGc = false;
    987             else if (strcmp(argv[i] + 5, "preverify") == 0)
    988                 gDvm.preVerify = true;
    989             else if (strcmp(argv[i] + 5, "nopreverify") == 0)
    990                 gDvm.preVerify = false;
    991             else if (strcmp(argv[i] + 5, "postverify") == 0)
    992                 gDvm.postVerify = true;
    993             else if (strcmp(argv[i] + 5, "nopostverify") == 0)
    994                 gDvm.postVerify = false;
    995             else if (strcmp(argv[i] + 5, "concurrent") == 0)
    996                 gDvm.concurrentMarkSweep = true;
    997             else if (strcmp(argv[i] + 5, "noconcurrent") == 0)
    998                 gDvm.concurrentMarkSweep = false;
    999             else if (strcmp(argv[i] + 5, "verifycardtable") == 0)
   1000                 gDvm.verifyCardTable = true;
   1001             else if (strcmp(argv[i] + 5, "noverifycardtable") == 0)
   1002                 gDvm.verifyCardTable = false;
   1003             else {
   1004                 dvmFprintf(stderr, "Bad value for -Xgc");
   1005                 return -1;
   1006             }
   1007             LOGV("Precise GC configured %s", gDvm.preciseGc ? "ON" : "OFF");
   1008 
   1009         } else if (strcmp(argv[i], "-Xcheckdexsum") == 0) {
   1010             gDvm.verifyDexChecksum = true;
   1011 
   1012         } else if (strcmp(argv[i], "-Xprofile:threadcpuclock") == 0) {
   1013             gDvm.profilerClockSource = kProfilerClockSourceThreadCpu;
   1014         } else if (strcmp(argv[i], "-Xprofile:wallclock") == 0) {
   1015             gDvm.profilerClockSource = kProfilerClockSourceWall;
   1016         } else if (strcmp(argv[i], "-Xprofile:dualclock") == 0) {
   1017             gDvm.profilerClockSource = kProfilerClockSourceDual;
   1018 
   1019         } else {
   1020             if (!ignoreUnrecognized) {
   1021                 dvmFprintf(stderr, "Unrecognized option '%s'\n", argv[i]);
   1022                 return -1;
   1023             }
   1024         }
   1025     }
   1026 
   1027     return 0;
   1028 }
   1029 
   1030 /*
   1031  * Set defaults for fields altered or modified by arguments.
   1032  *
   1033  * Globals are initialized to 0 (a/k/a NULL or false).
   1034  */
   1035 static void setCommandLineDefaults()
   1036 {
   1037     const char* envStr = getenv("CLASSPATH");
   1038     if (envStr != NULL) {
   1039         gDvm.classPathStr = strdup(envStr);
   1040     } else {
   1041         gDvm.classPathStr = strdup(".");
   1042     }
   1043     envStr = getenv("BOOTCLASSPATH");
   1044     if (envStr != NULL) {
   1045         gDvm.bootClassPathStr = strdup(envStr);
   1046     } else {
   1047         gDvm.bootClassPathStr = strdup(".");
   1048     }
   1049 
   1050     gDvm.properties = new std::vector<std::string>();
   1051 
   1052     /* Defaults overridden by -Xms and -Xmx.
   1053      * TODO: base these on a system or application-specific default
   1054      */
   1055     gDvm.heapStartingSize = 2 * 1024 * 1024;  // Spec says 16MB; too big for us.
   1056     gDvm.heapMaximumSize = 16 * 1024 * 1024;  // Spec says 75% physical mem
   1057     gDvm.heapGrowthLimit = 0;  // 0 means no growth limit
   1058     gDvm.stackSize = kDefaultStackSize;
   1059 
   1060     gDvm.concurrentMarkSweep = true;
   1061 
   1062     /* gDvm.jdwpSuspend = true; */
   1063 
   1064     /* allowed unless zygote config doesn't allow it */
   1065     gDvm.jdwpAllowed = true;
   1066 
   1067     /* default verification and optimization modes */
   1068     gDvm.classVerifyMode = VERIFY_MODE_ALL;
   1069     gDvm.dexOptMode = OPTIMIZE_MODE_VERIFIED;
   1070     gDvm.monitorVerification = false;
   1071     gDvm.generateRegisterMaps = true;
   1072     gDvm.registerMapMode = kRegisterMapModeTypePrecise;
   1073 
   1074     /*
   1075      * Default execution mode.
   1076      *
   1077      * This should probably interact with the mterp code somehow, e.g. if
   1078      * we know we're using the "desktop" build we should probably be
   1079      * using "portable" rather than "fast".
   1080      */
   1081 #if defined(WITH_JIT)
   1082     gDvm.executionMode = kExecutionModeJit;
   1083 #else
   1084     gDvm.executionMode = kExecutionModeInterpFast;
   1085 #endif
   1086 
   1087     /*
   1088      * SMP support is a compile-time define, but we may want to have
   1089      * dexopt target a differently-configured device.
   1090      */
   1091     gDvm.dexOptForSmp = (ANDROID_SMP != 0);
   1092 
   1093     /*
   1094      * Default profiler configuration.
   1095      */
   1096     gDvm.profilerClockSource = kProfilerClockSourceDual;
   1097 }
   1098 
   1099 
   1100 /*
   1101  * Handle a SIGBUS, which frequently occurs because somebody replaced an
   1102  * optimized DEX file out from under us.
   1103  */
   1104 static void busCatcher(int signum, siginfo_t* info, void* context)
   1105 {
   1106     void* addr = info->si_addr;
   1107 
   1108     LOGE("Caught a SIGBUS (%d), addr=%p", signum, addr);
   1109 
   1110     /*
   1111      * If we return at this point the SIGBUS just keeps happening, so we
   1112      * remove the signal handler and allow it to kill us.  TODO: restore
   1113      * the original, which points to a debuggerd stub; if we don't then
   1114      * debuggerd won't be notified.
   1115      */
   1116     signal(SIGBUS, SIG_DFL);
   1117 }
   1118 
   1119 /*
   1120  * Configure signals.  We need to block SIGQUIT so that the signal only
   1121  * reaches the dump-stack-trace thread.
   1122  *
   1123  * This can be disabled with the "-Xrs" flag.
   1124  */
   1125 static void blockSignals()
   1126 {
   1127     sigset_t mask;
   1128     int cc;
   1129 
   1130     sigemptyset(&mask);
   1131     sigaddset(&mask, SIGQUIT);
   1132     sigaddset(&mask, SIGUSR1);      // used to initiate heap dump
   1133 #if defined(WITH_JIT) && defined(WITH_JIT_TUNING)
   1134     sigaddset(&mask, SIGUSR2);      // used to investigate JIT internals
   1135 #endif
   1136     //sigaddset(&mask, SIGPIPE);
   1137     cc = sigprocmask(SIG_BLOCK, &mask, NULL);
   1138     assert(cc == 0);
   1139 
   1140     if (false) {
   1141         /* TODO: save the old sigaction in a global */
   1142         struct sigaction sa;
   1143         memset(&sa, 0, sizeof(sa));
   1144         sa.sa_sigaction = busCatcher;
   1145         sa.sa_flags = SA_SIGINFO;
   1146         cc = sigaction(SIGBUS, &sa, NULL);
   1147         assert(cc == 0);
   1148     }
   1149 }
   1150 
   1151 class ScopedShutdown {
   1152 public:
   1153     ScopedShutdown() : armed_(true) {
   1154     }
   1155 
   1156     ~ScopedShutdown() {
   1157         if (armed_) {
   1158             dvmShutdown();
   1159         }
   1160     }
   1161 
   1162     void disarm() {
   1163         armed_ = false;
   1164     }
   1165 
   1166 private:
   1167     bool armed_;
   1168 };
   1169 
   1170 /*
   1171  * VM initialization.  Pass in any options provided on the command line.
   1172  * Do not pass in the class name or the options for the class.
   1173  *
   1174  * Returns 0 on success.
   1175  */
   1176 std::string dvmStartup(int argc, const char* const argv[],
   1177         bool ignoreUnrecognized, JNIEnv* pEnv)
   1178 {
   1179     ScopedShutdown scopedShutdown;
   1180 
   1181     assert(gDvm.initializing);
   1182 
   1183     LOGV("VM init args (%d):", argc);
   1184     for (int i = 0; i < argc; i++) {
   1185         LOGV("  %d: '%s'", i, argv[i]);
   1186     }
   1187     setCommandLineDefaults();
   1188 
   1189     /*
   1190      * Process the option flags (if any).
   1191      */
   1192     int cc = processOptions(argc, argv, ignoreUnrecognized);
   1193     if (cc != 0) {
   1194         if (cc < 0) {
   1195             dvmFprintf(stderr, "\n");
   1196             usage("dalvikvm");
   1197         }
   1198         return "syntax error";
   1199     }
   1200 
   1201 #if WITH_EXTRA_GC_CHECKS > 1
   1202     /* only "portable" interp has the extra goodies */
   1203     if (gDvm.executionMode != kExecutionModeInterpPortable) {
   1204         LOGI("Switching to 'portable' interpreter for GC checks");
   1205         gDvm.executionMode = kExecutionModeInterpPortable;
   1206     }
   1207 #endif
   1208 
   1209     /* Configure group scheduling capabilities */
   1210     if (!access("/dev/cpuctl/tasks", F_OK)) {
   1211         LOGV("Using kernel group scheduling");
   1212         gDvm.kernelGroupScheduling = 1;
   1213     } else {
   1214         LOGV("Using kernel scheduler policies");
   1215     }
   1216 
   1217     /* configure signal handling */
   1218     if (!gDvm.reduceSignals)
   1219         blockSignals();
   1220 
   1221     /* verify system page size */
   1222     if (sysconf(_SC_PAGESIZE) != SYSTEM_PAGE_SIZE) {
   1223         return StringPrintf("expected page size %d, got %d",
   1224                 SYSTEM_PAGE_SIZE, (int) sysconf(_SC_PAGESIZE));
   1225     }
   1226 
   1227     /* mterp setup */
   1228     LOGV("Using executionMode %d", gDvm.executionMode);
   1229     dvmCheckAsmConstants();
   1230 
   1231     /*
   1232      * Initialize components.
   1233      */
   1234     if (!dvmAllocTrackerStartup()) {
   1235         return "dvmAllocTrackerStartup failed";
   1236     }
   1237     if (!dvmGcStartup()) {
   1238         return "dvmGcStartup failed";
   1239     }
   1240     if (!dvmThreadStartup()) {
   1241         return "dvmThreadStartup failed";
   1242     }
   1243     if (!dvmInlineNativeStartup()) {
   1244         return "dvmInlineNativeStartup";
   1245     }
   1246     if (!dvmRegisterMapStartup()) {
   1247         return "dvmRegisterMapStartup failed";
   1248     }
   1249     if (!dvmInstanceofStartup()) {
   1250         return "dvmInstanceofStartup failed";
   1251     }
   1252     if (!dvmClassStartup()) {
   1253         return "dvmClassStartup failed";
   1254     }
   1255 
   1256     /*
   1257      * At this point, the system is guaranteed to be sufficiently
   1258      * initialized that we can look up classes and class members. This
   1259      * call populates the gDvm instance with all the class and member
   1260      * references that the VM wants to use directly.
   1261      */
   1262     if (!dvmFindRequiredClassesAndMembers()) {
   1263         return "dvmFindRequiredClassesAndMembers failed";
   1264     }
   1265 
   1266     if (!dvmStringInternStartup()) {
   1267         return "dvmStringInternStartup failed";
   1268     }
   1269     if (!dvmNativeStartup()) {
   1270         return "dvmNativeStartup failed";
   1271     }
   1272     if (!dvmInternalNativeStartup()) {
   1273         return "dvmInternalNativeStartup failed";
   1274     }
   1275     if (!dvmJniStartup()) {
   1276         return "dvmJniStartup failed";
   1277     }
   1278     if (!dvmProfilingStartup()) {
   1279         return "dvmProfilingStartup failed";
   1280     }
   1281 
   1282     /*
   1283      * Create a table of methods for which we will substitute an "inline"
   1284      * version for performance.
   1285      */
   1286     if (!dvmCreateInlineSubsTable()) {
   1287         return "dvmCreateInlineSubsTable failed";
   1288     }
   1289 
   1290     /*
   1291      * Miscellaneous class library validation.
   1292      */
   1293     if (!dvmValidateBoxClasses()) {
   1294         return "dvmValidateBoxClasses failed";
   1295     }
   1296 
   1297     /*
   1298      * Do the last bits of Thread struct initialization we need to allow
   1299      * JNI calls to work.
   1300      */
   1301     if (!dvmPrepMainForJni(pEnv)) {
   1302         return "dvmPrepMainForJni failed";
   1303     }
   1304 
   1305     /*
   1306      * Explicitly initialize java.lang.Class.  This doesn't happen
   1307      * automatically because it's allocated specially (it's an instance
   1308      * of itself).  Must happen before registration of system natives,
   1309      * which make some calls that throw assertions if the classes they
   1310      * operate on aren't initialized.
   1311      */
   1312     if (!dvmInitClass(gDvm.classJavaLangClass)) {
   1313         return "couldn't initialized java.lang.Class";
   1314     }
   1315 
   1316     /*
   1317      * Register the system native methods, which are registered through JNI.
   1318      */
   1319     if (!registerSystemNatives(pEnv)) {
   1320         return "couldn't register system natives";
   1321     }
   1322 
   1323     /*
   1324      * Do some "late" initialization for the memory allocator.  This may
   1325      * allocate storage and initialize classes.
   1326      */
   1327     if (!dvmCreateStockExceptions()) {
   1328         return "dvmCreateStockExceptions failed";
   1329     }
   1330 
   1331     /*
   1332      * At this point, the VM is in a pretty good state.  Finish prep on
   1333      * the main thread (specifically, create a java.lang.Thread object to go
   1334      * along with our Thread struct).  Note we will probably be executing
   1335      * some interpreted class initializer code in here.
   1336      */
   1337     if (!dvmPrepMainThread()) {
   1338         return "dvmPrepMainThread failed";
   1339     }
   1340 
   1341     /*
   1342      * Make sure we haven't accumulated any tracked references.  The main
   1343      * thread should be starting with a clean slate.
   1344      */
   1345     if (dvmReferenceTableEntries(&dvmThreadSelf()->internalLocalRefTable) != 0)
   1346     {
   1347         LOGW("Warning: tracked references remain post-initialization");
   1348         dvmDumpReferenceTable(&dvmThreadSelf()->internalLocalRefTable, "MAIN");
   1349     }
   1350 
   1351     /* general debugging setup */
   1352     if (!dvmDebuggerStartup()) {
   1353         return "dvmDebuggerStartup failed";
   1354     }
   1355 
   1356     if (!dvmGcStartupClasses()) {
   1357         return "dvmGcStartupClasses failed";
   1358     }
   1359 
   1360     /*
   1361      * Init for either zygote mode or non-zygote mode.  The key difference
   1362      * is that we don't start any additional threads in Zygote mode.
   1363      */
   1364     if (gDvm.zygote) {
   1365         if (!initZygote()) {
   1366             return "initZygote failed";
   1367         }
   1368     } else {
   1369         if (!dvmInitAfterZygote()) {
   1370             return "dvmInitAfterZygote failed";
   1371         }
   1372     }
   1373 
   1374 
   1375 #ifndef NDEBUG
   1376     if (!dvmTestHash())
   1377         LOGE("dvmTestHash FAILED");
   1378     if (false /*noisy!*/ && !dvmTestIndirectRefTable())
   1379         LOGE("dvmTestIndirectRefTable FAILED");
   1380 #endif
   1381 
   1382     if (dvmCheckException(dvmThreadSelf())) {
   1383         dvmLogExceptionStackTrace();
   1384         return "Exception pending at end of VM initialization";
   1385     }
   1386 
   1387     scopedShutdown.disarm();
   1388     return "";
   1389 }
   1390 
   1391 /*
   1392  * Register java.* natives from our class libraries.  We need to do
   1393  * this after we're ready for JNI registration calls, but before we
   1394  * do any class initialization.
   1395  *
   1396  * If we get this wrong, we will blow up in the ThreadGroup class init if
   1397  * interpreted code makes any reference to System.  It will likely do this
   1398  * since it wants to do some java.io.File setup (e.g. for static in/out/err).
   1399  *
   1400  * We need to have gDvm.initializing raised here so that JNI FindClass
   1401  * won't try to use the system/application class loader.
   1402  */
   1403 static bool registerSystemNatives(JNIEnv* pEnv)
   1404 {
   1405     Thread* self;
   1406 
   1407     /* main thread is always first in list */
   1408     self = gDvm.threadList;
   1409 
   1410     /* must set this before allowing JNI-based method registration */
   1411     self->status = THREAD_NATIVE;
   1412 
   1413     if (jniRegisterSystemMethods(pEnv) < 0) {
   1414         LOGE("jniRegisterSystemMethods failed");
   1415         return false;
   1416     }
   1417 
   1418     /* back to run mode */
   1419     self->status = THREAD_RUNNING;
   1420 
   1421     return true;
   1422 }
   1423 
   1424 
   1425 /*
   1426  * Do zygote-mode-only initialization.
   1427  */
   1428 static bool initZygote()
   1429 {
   1430     /* zygote goes into its own process group */
   1431     setpgid(0,0);
   1432 
   1433     return true;
   1434 }
   1435 
   1436 /*
   1437  * Do non-zygote-mode initialization.  This is done during VM init for
   1438  * standard startup, or after a "zygote fork" when creating a new process.
   1439  */
   1440 bool dvmInitAfterZygote()
   1441 {
   1442     u8 startHeap, startQuit, startJdwp;
   1443     u8 endHeap, endQuit, endJdwp;
   1444 
   1445     startHeap = dvmGetRelativeTimeUsec();
   1446 
   1447     /*
   1448      * Post-zygote heap initialization, including starting
   1449      * the HeapWorker thread.
   1450      */
   1451     if (!dvmGcStartupAfterZygote())
   1452         return false;
   1453 
   1454     endHeap = dvmGetRelativeTimeUsec();
   1455     startQuit = dvmGetRelativeTimeUsec();
   1456 
   1457     /* start signal catcher thread that dumps stacks on SIGQUIT */
   1458     if (!gDvm.reduceSignals && !gDvm.noQuitHandler) {
   1459         if (!dvmSignalCatcherStartup())
   1460             return false;
   1461     }
   1462 
   1463     /* start stdout/stderr copier, if requested */
   1464     if (gDvm.logStdio) {
   1465         if (!dvmStdioConverterStartup())
   1466             return false;
   1467     }
   1468 
   1469     endQuit = dvmGetRelativeTimeUsec();
   1470     startJdwp = dvmGetRelativeTimeUsec();
   1471 
   1472     /*
   1473      * Start JDWP thread.  If the command-line debugger flags specified
   1474      * "suspend=y", this will pause the VM.  We probably want this to
   1475      * come last.
   1476      */
   1477     if (!initJdwp()) {
   1478         LOGD("JDWP init failed; continuing anyway");
   1479     }
   1480 
   1481     endJdwp = dvmGetRelativeTimeUsec();
   1482 
   1483     LOGV("thread-start heap=%d quit=%d jdwp=%d total=%d usec",
   1484         (int)(endHeap-startHeap), (int)(endQuit-startQuit),
   1485         (int)(endJdwp-startJdwp), (int)(endJdwp-startHeap));
   1486 
   1487 #ifdef WITH_JIT
   1488     if (gDvm.executionMode == kExecutionModeJit) {
   1489         if (!dvmCompilerStartup())
   1490             return false;
   1491     }
   1492 #endif
   1493 
   1494     return true;
   1495 }
   1496 
   1497 /*
   1498  * Prepare for a connection to a JDWP-compliant debugger.
   1499  *
   1500  * Note this needs to happen fairly late in the startup process, because
   1501  * we need to have all of the java.* native methods registered (which in
   1502  * turn requires JNI to be fully prepped).
   1503  *
   1504  * There are several ways to initialize:
   1505  *   server=n
   1506  *     We immediately try to connect to host:port.  Bail on failure.  On
   1507  *     success, send VM_START (suspending the VM if "suspend=y").
   1508  *   server=y suspend=n
   1509  *     Passively listen for a debugger to connect.  Return immediately.
   1510  *   server=y suspend=y
   1511  *     Wait until debugger connects.  Send VM_START ASAP, suspending the
   1512  *     VM after the message is sent.
   1513  *
   1514  * This gets more complicated with a nonzero value for "timeout".
   1515  */
   1516 static bool initJdwp()
   1517 {
   1518     assert(!gDvm.zygote);
   1519 
   1520     /*
   1521      * Init JDWP if the debugger is enabled.  This may connect out to a
   1522      * debugger, passively listen for a debugger, or block waiting for a
   1523      * debugger.
   1524      */
   1525     if (gDvm.jdwpAllowed && gDvm.jdwpConfigured) {
   1526         JdwpStartupParams params;
   1527 
   1528         if (gDvm.jdwpHost != NULL) {
   1529             if (strlen(gDvm.jdwpHost) >= sizeof(params.host)-1) {
   1530                 LOGE("ERROR: hostname too long: '%s'", gDvm.jdwpHost);
   1531                 return false;
   1532             }
   1533             strcpy(params.host, gDvm.jdwpHost);
   1534         } else {
   1535             params.host[0] = '\0';
   1536         }
   1537         params.transport = gDvm.jdwpTransport;
   1538         params.server = gDvm.jdwpServer;
   1539         params.suspend = gDvm.jdwpSuspend;
   1540         params.port = gDvm.jdwpPort;
   1541 
   1542         gDvm.jdwpState = dvmJdwpStartup(&params);
   1543         if (gDvm.jdwpState == NULL) {
   1544             LOGW("WARNING: debugger thread failed to initialize");
   1545             /* TODO: ignore? fail? need to mimic "expected" behavior */
   1546         }
   1547     }
   1548 
   1549     /*
   1550      * If a debugger has already attached, send the "welcome" message.  This
   1551      * may cause us to suspend all threads.
   1552      */
   1553     if (dvmJdwpIsActive(gDvm.jdwpState)) {
   1554         //dvmChangeStatus(NULL, THREAD_RUNNING);
   1555         if (!dvmJdwpPostVMStart(gDvm.jdwpState, gDvm.jdwpSuspend)) {
   1556             LOGW("WARNING: failed to post 'start' message to debugger");
   1557             /* keep going */
   1558         }
   1559         //dvmChangeStatus(NULL, THREAD_NATIVE);
   1560     }
   1561 
   1562     return true;
   1563 }
   1564 
   1565 /*
   1566  * An alternative to JNI_CreateJavaVM/dvmStartup that does the first bit
   1567  * of initialization and then returns with "initializing" still set.  (Used
   1568  * by DexOpt command-line utility.)
   1569  *
   1570  * Attempting to use JNI or internal natives will fail.  It's best
   1571  * if no bytecode gets executed, which means no <clinit>, which means
   1572  * no exception-throwing.  (In practice we need to initialize Class and
   1573  * Object, and probably some exception classes.)
   1574  *
   1575  * Returns 0 on success.
   1576  */
   1577 int dvmPrepForDexOpt(const char* bootClassPath, DexOptimizerMode dexOptMode,
   1578     DexClassVerifyMode verifyMode, int dexoptFlags)
   1579 {
   1580     gDvm.initializing = true;
   1581     gDvm.optimizing = true;
   1582 
   1583     /* configure signal handling */
   1584     blockSignals();
   1585 
   1586     /* set some defaults */
   1587     setCommandLineDefaults();
   1588     free(gDvm.bootClassPathStr);
   1589     gDvm.bootClassPathStr = strdup(bootClassPath);
   1590 
   1591     /* set opt/verify modes */
   1592     gDvm.dexOptMode = dexOptMode;
   1593     gDvm.classVerifyMode = verifyMode;
   1594     gDvm.generateRegisterMaps = (dexoptFlags & DEXOPT_GEN_REGISTER_MAPS) != 0;
   1595     if (dexoptFlags & DEXOPT_SMP) {
   1596         assert((dexoptFlags & DEXOPT_UNIPROCESSOR) == 0);
   1597         gDvm.dexOptForSmp = true;
   1598     } else if (dexoptFlags & DEXOPT_UNIPROCESSOR) {
   1599         gDvm.dexOptForSmp = false;
   1600     } else {
   1601         gDvm.dexOptForSmp = (ANDROID_SMP != 0);
   1602     }
   1603 
   1604     /*
   1605      * Initialize the heap, some basic thread control mutexes, and
   1606      * get the bootclasspath prepped.
   1607      *
   1608      * We can't load any classes yet because we may not yet have a source
   1609      * for things like java.lang.Object and java.lang.Class.
   1610      */
   1611     if (!dvmGcStartup())
   1612         goto fail;
   1613     if (!dvmThreadStartup())
   1614         goto fail;
   1615     if (!dvmInlineNativeStartup())
   1616         goto fail;
   1617     if (!dvmRegisterMapStartup())
   1618         goto fail;
   1619     if (!dvmInstanceofStartup())
   1620         goto fail;
   1621     if (!dvmClassStartup())
   1622         goto fail;
   1623 
   1624     /*
   1625      * We leave gDvm.initializing set to "true" so that, if we're not
   1626      * able to process the "core" classes, we don't go into a death-spin
   1627      * trying to throw a "class not found" exception.
   1628      */
   1629 
   1630     return 0;
   1631 
   1632 fail:
   1633     dvmShutdown();
   1634     return 1;
   1635 }
   1636 
   1637 
   1638 /*
   1639  * All threads have stopped.  Finish the shutdown procedure.
   1640  *
   1641  * We can also be called if startup fails partway through, so be prepared
   1642  * to deal with partially initialized data.
   1643  *
   1644  * Free any storage allocated in gGlobals.
   1645  *
   1646  * We can't dlclose() shared libs we've loaded, because it's possible a
   1647  * thread not associated with the VM is running code in one.
   1648  *
   1649  * This is called from the JNI DestroyJavaVM function, which can be
   1650  * called from any thread.  (In practice, this will usually run in the
   1651  * same thread that started the VM, a/k/a the main thread, but we don't
   1652  * want to assume that.)
   1653  */
   1654 void dvmShutdown()
   1655 {
   1656     LOGV("VM shutting down");
   1657 
   1658     if (CALC_CACHE_STATS)
   1659         dvmDumpAtomicCacheStats(gDvm.instanceofCache);
   1660 
   1661     /*
   1662      * Stop our internal threads.
   1663      */
   1664     dvmGcThreadShutdown();
   1665 
   1666     if (gDvm.jdwpState != NULL)
   1667         dvmJdwpShutdown(gDvm.jdwpState);
   1668     free(gDvm.jdwpHost);
   1669     gDvm.jdwpHost = NULL;
   1670     free(gDvm.jniTrace);
   1671     gDvm.jniTrace = NULL;
   1672     free(gDvm.stackTraceFile);
   1673     gDvm.stackTraceFile = NULL;
   1674 
   1675     /* tell signal catcher to shut down if it was started */
   1676     dvmSignalCatcherShutdown();
   1677 
   1678     /* shut down stdout/stderr conversion */
   1679     dvmStdioConverterShutdown();
   1680 
   1681 #ifdef WITH_JIT
   1682     if (gDvm.executionMode == kExecutionModeJit) {
   1683         /* shut down the compiler thread */
   1684         dvmCompilerShutdown();
   1685     }
   1686 #endif
   1687 
   1688     /*
   1689      * Kill any daemon threads that still exist.  Actively-running threads
   1690      * are likely to crash the process if they continue to execute while
   1691      * the VM shuts down.
   1692      */
   1693     dvmSlayDaemons();
   1694 
   1695     if (gDvm.verboseShutdown)
   1696         LOGD("VM cleaning up");
   1697 
   1698     dvmDebuggerShutdown();
   1699     dvmProfilingShutdown();
   1700     dvmJniShutdown();
   1701     dvmStringInternShutdown();
   1702     dvmThreadShutdown();
   1703     dvmClassShutdown();
   1704     dvmRegisterMapShutdown();
   1705     dvmInstanceofShutdown();
   1706     dvmInlineNativeShutdown();
   1707     dvmGcShutdown();
   1708     dvmAllocTrackerShutdown();
   1709 
   1710     /* these must happen AFTER dvmClassShutdown has walked through class data */
   1711     dvmNativeShutdown();
   1712     dvmInternalNativeShutdown();
   1713 
   1714     dvmFreeInlineSubsTable();
   1715 
   1716     free(gDvm.bootClassPathStr);
   1717     free(gDvm.classPathStr);
   1718     delete gDvm.properties;
   1719 
   1720     freeAssertionCtrl();
   1721 
   1722     /*
   1723      * We want valgrind to report anything we forget to free as "definitely
   1724      * lost".  If there's a pointer in the global chunk, it would be reported
   1725      * as "still reachable".  Erasing the memory fixes this.
   1726      *
   1727      * This must be erased to zero if we want to restart the VM within this
   1728      * process.
   1729      */
   1730     memset(&gDvm, 0xcd, sizeof(gDvm));
   1731 }
   1732 
   1733 
   1734 /*
   1735  * fprintf() wrapper that calls through the JNI-specified vfprintf hook if
   1736  * one was specified.
   1737  */
   1738 int dvmFprintf(FILE* fp, const char* format, ...)
   1739 {
   1740     va_list args;
   1741     int result;
   1742 
   1743     va_start(args, format);
   1744     if (gDvm.vfprintfHook != NULL)
   1745         result = (*gDvm.vfprintfHook)(fp, format, args);
   1746     else
   1747         result = vfprintf(fp, format, args);
   1748     va_end(args);
   1749 
   1750     return result;
   1751 }
   1752 
   1753 #ifdef __GLIBC__
   1754 #include <execinfo.h>
   1755 /*
   1756  * glibc-only stack dump function.  Requires link with "--export-dynamic".
   1757  *
   1758  * TODO: move this into libs/cutils and make it work for all platforms.
   1759  */
   1760 void dvmPrintNativeBackTrace()
   1761 {
   1762     size_t MAX_STACK_FRAMES = 64;
   1763     void* stackFrames[MAX_STACK_FRAMES];
   1764     size_t frameCount = backtrace(stackFrames, MAX_STACK_FRAMES);
   1765 
   1766     /*
   1767      * TODO: in practice, we may find that we should use backtrace_symbols_fd
   1768      * to avoid allocation, rather than use our own custom formatting.
   1769      */
   1770     char** strings = backtrace_symbols(stackFrames, frameCount);
   1771     if (strings == NULL) {
   1772         LOGE("backtrace_symbols failed: %s", strerror(errno));
   1773         return;
   1774     }
   1775 
   1776     size_t i;
   1777     for (i = 0; i < frameCount; ++i) {
   1778         LOGW("#%-2d %s", i, strings[i]);
   1779     }
   1780     free(strings);
   1781 }
   1782 #else
   1783 void dvmPrintNativeBackTrace() {
   1784     /* Hopefully, you're on an Android device and debuggerd will do this. */
   1785 }
   1786 #endif
   1787 
   1788 /*
   1789  * Abort the VM.  We get here on fatal errors.  Try very hard not to use
   1790  * this; whenever possible, return an error to somebody responsible.
   1791  */
   1792 void dvmAbort()
   1793 {
   1794     /*
   1795      * Leave gDvm.lastMessage on the stack frame which can be decoded in the
   1796      * tombstone file. This is for situations where we only have tombstone files
   1797      * but no logs (ie b/5372634).
   1798      *
   1799      * For example, in the tombstone file you usually see this:
   1800      *
   1801      *   #00  pc 00050ef2  /system/lib/libdvm.so (dvmAbort)
   1802      *   #01  pc 00077670  /system/lib/libdvm.so (_Z15dvmClassStartupv)
   1803      *     :
   1804      *
   1805      * stack:
   1806      *     :
   1807      * #00 beed2658  00000000
   1808      *     beed265c  7379732f
   1809      *     beed2660  2f6d6574
   1810      *     beed2664  6d617266
   1811      *     beed2668  726f7765
   1812      *     beed266c  6f632f6b
   1813      *     beed2670  6a2e6572
   1814      *     beed2674  00007261
   1815      *     beed2678  00000000
   1816      *
   1817      * The ascii values between beed265c and beed2674 belongs to messageBuffer
   1818      * and it can be decoded as "/system/framework/core.jar".
   1819      */
   1820     const int messageLength = 512;
   1821     char messageBuffer[messageLength] = {0};
   1822     int result = 0;
   1823 
   1824     snprintf(messageBuffer, messageLength, "%s", gDvm.lastMessage);
   1825 
   1826     /* So that messageBuffer[] looks like useful stuff to the compiler */
   1827     for (int i = 0; i < messageLength && messageBuffer[i]; i++) {
   1828         result += messageBuffer[i];
   1829     }
   1830 
   1831     LOGE("VM aborting");
   1832 
   1833     fflush(NULL);       // flush all open file buffers
   1834 
   1835     /* JNI-supplied abort hook gets right of first refusal */
   1836     if (gDvm.abortHook != NULL)
   1837         (*gDvm.abortHook)();
   1838 
   1839     /*
   1840      * On the device, debuggerd will give us a stack trace.
   1841      * On the host, we have to help ourselves.
   1842      */
   1843     dvmPrintNativeBackTrace();
   1844 
   1845     /*
   1846      * If we call abort(), all threads in the process receives a SIBABRT.
   1847      * debuggerd dumps the stack trace of the main thread, whether or not
   1848      * that was the thread that failed.
   1849      *
   1850      * By stuffing a value into a bogus address, we cause a segmentation
   1851      * fault in the current thread, and get a useful log from debuggerd.
   1852      * We can also trivially tell the difference between a VM crash and
   1853      * a deliberate abort by looking at the fault address.
   1854      */
   1855     *((char*)0xdeadd00d) = result;
   1856     abort();
   1857 
   1858     /* notreached */
   1859 }
   1860